An explosion tore through a crowded railway station in the provincial Chinese capital of Xinjiang last night, hours after President Xi Jinping had left the city and described the troubled western region as the nation’s “front line against terrorism”.

At least three people were killed and 79 injured in the blast, which followed a number of deadly incidents involving members of Xinjiang’s Uighur Muslim minority since the start of the year.

The explosion appeared to be a humiliating security lapse, not only because Mr Xi had been in the city earlier that day, but because he had specifically used his